They return to action against Samoa on Friday night and Halfpenny admits he and his teammates are determined to get back on track.
"We didn't meet the standards we set ourselves against Argentina," said Halfpenny.
"Our ability to keep the ball wasn't good enough. We pride ourselves on our fitness and our ability to keep the ball but we weren't able to build that pressure.
"They slowed our ball down a lot and every time we attacked them there was a wall of white and blue jerseys in front of us.
"For us as players and a whole squad it's how we bounce back, how we react from Saturday. I just can't wait to get back on the pitch playing. We worked hard over the last two weeks and I guess we'll have to work harder now.
"Over the series, the longer we spend together the stronger we'll get. I've had a lot of highs in the Welsh jersey and a couple of lows and that was one of the lows on Saturday.
"It's hard to take as a player but that's rugby. All we can do now is look at our video analysis and improve. To be honest getting out on that training pitch can't come soon enough for me and we can start putting things right."
Wales returned to training yesterday and welcome Samoa to the Millennium Stadium, following their 42-12 victory, on Friday.
And Halfpenny, who created the match-winning try against the South Sea Islanders during the World Cup, expects another physical challenge.
"With Samoa it goes without saying they're a hugely physical team and they have that unknown about them that they can create something out of nothing," added Halfpenny.
"They have players with a lot of flair and a lot of running ability. They're able to offload and have a lot of skilful players so it will be a physical and fast game.
"We need to stick to our structures, not let the game go loose and match them physically."